Struct near_contract_tools::slot::Slot

pub struct Slot<T> {
    pub key: Vec<u8>,
    /* private fields */
}

A storage slot, composed of a storage location (key) and a data type

Fields

key: Vec<u8>

The storage key this slot controls

Implementations

impl Slot<()>

pub fn root<K: IntoStorageKey>(key: K) -> Self

A placeholder slot. Useful for creating namespaced fields.

impl<T> Slot<T>

pub fn new(key: impl IntoStorageKey) -> Self

Creates a new Slot that controls the given storage key

pub fn ns(&self, key: impl IntoStorageKey) -> Slot<()>

Creates a new Slot that controls the given key namespaced (prefixed) by the parent key, to be used as a namespace for another subfield.

pub fn field<U>(&self, key: impl IntoStorageKey) -> Slot<U>

Creates a new Slot that controls the given key namespaced (prefixed) by the parent key.

pub fn transmute<U>(&self) -> Slot<U>

Creates a Slot that tries to parse a different data type from the same storage slot.

Warning

If the data in the slot is not parsable into the new type, methods like Slot::read and Slot::take will panic.

pub fn write_raw(&mut self, value: &[u8]) -> bool

Write raw bytes into the storage slot. No type checking.

pub fn read_raw(&self) -> Option<Vec<u8>>

Read raw bytes from the slot. No type checking or parsing.

pub fn exists(&self) -> bool

Returns true if this slot’s key is currently present in the smart contract storage, false otherwise

pub fn remove(&mut self) -> bool

Removes the managed key from storage

impl<T: BorshSerialize> Slot<T>

pub fn write(&mut self, value: &T) -> bool

Writes a value to the managed storage slot

pub fn set(&mut self, value: Option<&T>) -> bool

If the given value is Some(T), writes T to storage. Otherwise, removes the key from storage.

Use of this method makes the slot function similarly to [near_sdk::collections::LazyOption].

impl<T: BorshDeserialize> Slot<T>

pub fn read(&self) -> Option<T>

Reads a value from storage, if present.

pub fn take(&mut self) -> Option<T>

Removes a value from storage and returns it if present.

impl<T: BorshSerialize + BorshDeserialize> Slot<T>

pub fn swap(&mut self, value: &T) -> Option<T>

Writes a value to storage and returns the evicted value, if present.

Trait Implementations

impl<T> BorshDeserialize for Slot<T>where
    Vec<u8>: BorshDeserialize,

fn deserialize(buf: &mut &[u8]) -> Result<Self, Error>

Deserializes this instance from a given slice of bytes. Updates the buffer to point at the remaining bytes.

fn try_from_slice(v: &[u8]) -> Result<Self, Error>

Deserialize this instance from a slice of bytes.

impl<T> BorshSerialize for Slot<T>where
    Vec<u8>: BorshSerialize,

fn serialize<W: Write>(&self, writer: &mut W) -> Result<(), Error>

fn try_to_vec(&self) -> Result<Vec<u8, Global>, Error>

Serialize this instance into a vector of bytes.

impl<T: Clone> Clone for Slot<T>

fn clone(&self) -> Slot<T>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Debug> Debug for Slot<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T> IntoStorageKey for Slot<T>

fn into_storage_key(self) -> Vec<u8>

Consumes self and returns Vec<u8> bytes which are used as a storage key.

impl<T, U> PartialEq<Slot<U>> for Slot<T>

fn eq(&self, other: &Slot<U>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.